A ward is a group of rooms or a section in a hospital or prison; in a hospital, different wards deal with different needs, like the psychiatric ward or maternity ward.
Although ward is most often used in connection with hospitals and prisons, cities and towns can also be broken into wards. These are usually geographic areas that are used in elections: city council members often represent wards of the city. A ward is also the name given to a child who is watched over by someone other than his parents. Sometimes children are known as "wards of the state," meaning they have been taken from their homes.